With the rapid development of Internet technology and the great popularization of large-screen multifunctional mobile terminals, mobile data multimedia services and various high-bandwidth multimedia services, commonly including video sessions, television broadcasts, video on demand, advertisements, online education, interactive games and the like, are applied and promoted on a large scale. The application and promotion of these multimedia services not only meet multi-service demands of a mobile user, but also facilitate new service increase of a mobile operator. These mobile data multimedia services require multiple users to be able to receive the same data simultaneously. Compared with general data services, the mobile data multimedia services have the characteristics of large data volume, long duration, delay sensitivity and the like.
In order to effectively utilize mobile network resources, a 3rd Generation Partnership Project (3GPP) proposes Multimedia Broadcast Multicast Service (MBMS). The MBMS is a technology of transmitting data from a data source to multiple target mobile terminals, thereby sharing resources of networks (including a core network and an access network), and improving the utilization rate of network resources (particularly air interface resources). The MBMS defined by the 3GPP not only can realize plain-text low-rate message multicast and broadcast, but also can realize multimedia service broadcast and multicast. Various rich videos and audios are provided for multimedia services, which complies with the future development trend of mobile data without doubt and provides a better service prospect for the development of mobile communications.
The MBMS has the characteristics of large service data volume, long receiving duration of a mobile terminal and constant average data rate. The above-mentioned characteristics determine that scheduling and control signaling configurations of the MBMS are semi-static. That is, scheduling information and control signaling information of the MBMS remain unchanged ‘for a long time’. These pieces of information are periodically sent through an MBMS Control Channel (MCCH), and are collectively referred to as MCCH information. An evolved MBMS (eMBMS) system may have multiple MCCHs, each MCCH corresponds to a different MBMS Single Frequency Network (MBSFN) region, herein control information of the MBMS sent by the corresponding MBSFN region is only borne.
An MBMS notification message is used for describing whether MCCH information changes. User Equipment (UE) in a mode of Radio Resource Control Idle (RRC Idle) or RRC Connected UE can know whether the MCCH information changes by only monitoring the MBMS notification message, so as to selectively receive the MCCH information. That is, only when the MCCH information changes, new MCCH information is received. The information amount of the MBMS notification message is much less than that of the MCCH information, so the UE selectively receives the MCCH information, resources can be effectively saved, and the power consumption is reduced. The MBMS notification message is borne on a Physical Downlink Control Channel (PDCCH) of a specified MBSFN subframe and periodically sent, and the MBSFN subframe and a sending period are indicated by a system message (System Information Block (SIB) 13) accordingly.
In a Long Term Evolution (LTE) system, UE (or referred to as a terminal) is notified that a certain MBMS will be subjected to session start or a network side initiates a counting request. Downlink Control Information (DCI) and an MBMS-Radio Network Temporary Identifier (RNTI) (M-RNTI) may be sent on a PDCCH first. The UE selectively reads a specific MCCH message according to information in the DCI, which is referred to as an MCCH change notification mechanism. Specific service configuration parameters such as a service ID, service Radio Link Control (RLC), Media Access Control (MAC) and physical layer configuration parameters will be sent on the MCCH message.
At present, MBMS technology is introduced into an LTE system of a Release 9 (R9), and an LTE system of a Release 10 (R10) is enhanced. In R9, control signaling and use data of MBMS are transmitted separately on a Control Plane (CP) and a User Plane (UP). The CP controls sending of the UP user data by controlling the start, update and end of the service, so as to achieve basic MBMS sending. The MBMS is sent in an MBSFN region with a fixed size (which may be configured statically or semi-statically). MBMS scheduling information is indicated by Multicast Channel (MCH) Scheduling Information (MSI) on the MBSFN subframe, and the MBMS is multiplexed in a time domain.
The 3GPP proposes a research project about single-cell MBMS in LTE-Advanced (LTE-A) of a Release 13 (R13), wherein the single-cell MBMS is transmitted on a Physical Downlink Share Channel (PDSCH), the process being referred to as Single Cell-Point To Multipoint (SC-PTM).
The PDCCH is indicating information for parsing data of the PDSCH. Therefore, the PDCCH is ahead of the PDSCH (data domain) in a time domain, and namely occupies the first, second, third and fourth symbols of a subframe. FIG. 1 is a channel diagram illustrating that a PDCCH occupies three symbols in a subframe in the existing technology. As shown in FIG. 1, a horizontal grid represents a PDSCH, a vertical grid represents a PDCCH, a left oblique grid represents a Physical Control Format Indication Channel (PCFICH), a right oblique grid represents a Physical Hybrid automatic repeat request Indicator Channel (PHICH), a black bar frame represents a Reference Signal (RS), and a white bar frame represents a Physical Broadcast Channel (PBCH). DCI sent in the PDCCH is used for indicating information such as resource configuration of the PDSCH, uplink resource license, and the like. A Cyclic Redundancy Check (CRC) at the tail of the PDCCH is 16 bits, and is scrambled by using a specific RNTI, the RNTI is used for identifying a UE or a specific purpose. The UE performs blind detection (blind detection refers to searching for a bit sequence obtained by descrambling by the UE in the absence of prior information) on the PDCCH of the received subframe to obtain a required control signaling. The blind detection is advantageous in no additional overhead and disadvantageous in high detection complexity. In order to reduce the complexity of searching, a concept of a search space is defined in TS36.213. Each UE searches for a control signaling in a specific search space, each search space containing a group of Control Channel Elements (CCE). The search space in LTE includes a common search space and a UE-specific search space.
In the above-mentioned service scheduling application, there are the following problems. Single-cell MBMS scheduling is greatly different from multi-cell MBMS (service scheduling indication through an MBSFN) scheduling: scheduling information of a PDSCH is transmitted on a PDCCH, the PDSCH may be multiplexed in a time domain, scheduling information of a Physical Multicast Channel (PMCH) is transmitted on MSI, and the PMCH can only be multiplexed in the time domain. Therefore, a multi-cell MBMS scheduling method cannot be used in the single-cell MBMS scheduling, and in view of difference between the MBMS and a unicast service, it is improper to dynamically schedule the MBMS on the PDCCH of each subframe. At present, there is no MBMS scheduling method suitable for single-cell transmission.